1. Field of the Invention
This invention relates generally to methods and apparatus for lining cardboard box blanks and particularly to methods and apparatus for lining bulk box blanks.
2. Background of the Invention
Several continuous and intermittent processes for incorporating support liners into cardboard box blanks are known in the art. For example, U.S. Pat. Nos. 2,432,053 issued to Waters on Dec. 2, 1947, 2,502,117 issued to Anderson on Mar. 28, 1950 and 3,772,121 issued to Peltier on Nov. 13, 1973 describe various methods for inserting liners into formed or unformed conventional box blanks.
However, the prior art conventional box lining approaches are not suitable for forming lined "bulk" box blanks. Bulk box blanks are very large box blanks designed for heavy duty applications. In the petro-chemical industry, for example, bulk boxes contain large quantities of heavy bulk chemicals. Bulk box blanks are conventionally of a size on the order of about 400 centimeters by about 125 centimeters and have a thickness of from 1 to 2 centimeters. These boxes must be lined with comparable liners to withstand the severe loads placed on them. Generally the blanks are extremely rigid and are therefore not amenable to easy processing. These extraordinary characteristics have hampered the development, in the prior art, of an automated continuous or intermittent process suitable for efficient commercial production of lined, tubular bulk box blanks.